import math
from unittest import result
def circlearea(r):
    result = math.pi*r*r
    return result
r= 10
print('半径为:',r,'圆的面积为:',circlearea(r))

import math
r = 10 
result = lambda r:math.pi*r*r
print('半径为:',r,'圆的面积为:',result(r))